


A killer's promise

by Genoscissors



Category: Danganronpa
Genre: Character spoilers for Korekiyo, F/M, Maybe they'll just be friends, Who Knows?, maybe they'll become lovers
Language: English
Status: Completed
Published: 2017-08-03
Updated: 2017-09-16
Packaged: 2018-12-10 18:58:13
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 5
Words: 4,139
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/11697864
Author URL: https://archiveofourown.org/users/Genoscissors/pseuds/Genoscissors
Summary: Spoilers for Korekiyo Shinguuji.Toko fell in love with an underclassman, and Korekiyo became interested in her, but in a different way.





	1. Chapter 1

'Miss Fukawa, may I talk to you? Just for a moment.' Toko's latest obsession, the anthropologist from the year below, was interested in her. She was undoubtedly beautiful, but she possessed certain traits that made her desirable. She was shy but kind-hearted, a helpless romantic. She would make a fine friend for his sister. All he needed to do was to make her come with him, and then he could, shall we say, introduce the two.  
'Uh, sure Sh-shinguuji.' A blush covered her cheeks, how predictable. She had fallen for this handsome masked man, and she would do whatever he asked of her.

He took her to a cafe first, where the made small talk. It had the ambiance of a date, and Toko was enchanted. Compliments showered the girl, more than she'd ever received before. He came to the conclusion that she was indeed worthy, so he decided to put his plan in motion. He walked with her around town for a while, before saying:  
'You know, I think you're a wonderful girl. I would like to kiss you, if that's ok.'  
'I would love that, Shinguuji.' She had always dreamed of her first kiss, and this wasn't how she'd imagined it, but this was fine too.  
'Not here though, I only want you to see me under the mask. You're the only one I trust. Let's find somewhere quiet, if you're fine with that.' She was, obviously, so he took her to a dark alleyway, a favourite spot of his. 

He then removed a knife from his pocket, and drove it into her.  
Luckily, Toko was able to defend herself in time, so her arm was cut and not her heart. Unluckily, the sight of her own blood caused her to faint, putting her at Shinguuji's mercy. Or so he thought. He approached the body, expecting to be able the kill her quickly and silently. But she woke up again.  
This one was different, he thought. She was bolder, crazier, scarier. When he went to stab her again she lunged out and pinned him down to the ground. She then started to yell at him.  
'Who the hell are you and what did you do to Toko! If you dared hurt her, I swear you will die a slow and painful death, you hear me!' He could barely speak, the girl he had thought as worthy was now showing her true colours. How beautiful. How unworthy.

'I am Korekiyo Shinguuji, and I-' Genocider Syo kicked him in the face, before taking out her signature Genoscissors.  
'You're that guy are you, Toko talks about you a lot. Agh, anyone else would have been fine but you? With all the shit Toko gets she needs someone positive in her life, so she creates idols out of those close to her, you were one of them. If it was anyone else she would be fine, but you? It'll destroy her again.'  
'I-I' Korekiyo was shocked, this girl in front of him was completely different to the SHSL writer. Maybe it was a split personality? Either way, she would not be a good influence on his sister.  
'I'll give you one chance, you hear me? Apologise, and be nice to Toko. She needs a friend.'  
'And what about you? Can I be your friend too?'  
'Who would want to be friends with a serial killer?'  
'Another serial killer maybe... I'll apologise to her, I'll be the friend she needs, and I hope she can be the friend I need. And I'll be your friend too. And I won't kill you, after meeting you I realise you aren't the type I was looking for.'  
'The type?'  
And so he explained his reasons for murder.

Toko woke up later with a note from Genocider, and a perfectly bandaged wound, thanks to Korekiyo. She accepted his apology, but decided she didn't want to be in love with him anymore, and did all she could to erase all feelings of love. However, Genocider hadn't told the entire truth in the note, so she didn't know about Korekiyo's sister.


	2. Chapter 2

The day after she was attacked, Toko went to school as usual, and was greeted by Korekiyo as she went through the gates. She was nervous at first, but she remembered what the Genocider's note had said, and decided to ask him about it.  
'You kill people... right?'  
'Correct' He was very open about it, maybe too open.  
'Because you want them to be friends with your dead lover.'  
'That is also correct.'  
'That's romantic of you, is that what you think? Of course not. How can I be friends with a serial killer? It's bad enough that my split personality is one, but you too? I'd be in constant fear of my sudden death.' She suddenly grew more confidence than she thought she had. She had always been less shy around people she wasn't attracted too, but she'd never been this confrontational.  
'Don't worry, I wouldn't want Genocider to be friends with my sister. If she didn't exist you would be dead already, but I'm fine if you're friends with me instead of her.'  
'I already told you, I'm not- sister?' The note hadn't mentioned anything about a sister, so Toko wondered what he meant. Surely he meant lover.  
'My sister, yes, Miyadera Shinguuji, the person I kill people for.'  
'But the note said for your lover. Unless your sister was your lover.' Not just a serial killer, but an incestuous serial killer, this would make an interesting novel, but this was not the time for that.  
Korekiyo was silent for a second, realising that she had not been told the entire truth. He pondered over what to say to her, but finally decided, 'yes, she is.' He realised that the slim chances of being her friend had now vanished, but it would be easier than telling her later.

Just then, the bell signalling the start of classes rung. A teacher yelled at them to hurry up, and Toko was looking extremely nervous. Shinguuji was often late to class, as he got distracted by the beauty of others. He could have just left her, but he didn't.  
'What's wrong Miss Fukawa?'  
'I've never been l-late before. If I went now everyone would stare at me. I'd g-get yelled at too. Maybe they'd tell my parents, and then my mother would hit me and my mum would use it as an excuse to starve me again, so they could waste their money on gambling. Maybe they'd even-'  
'Fukawa, you don't need to worry, I will make sure you aren't late for class.'  
'But it's already started, unless you have a time machine you should stop giving me false hope.'  
'You can't be late if you never arrive. Let's just skip school and go somewhere else.'  
'L-like a dark alleyway you mean? Like hell I'd do that. Besides, I'd miss classes, and therefore not be able to catch up on my studies, meaning I'd fail my classes, and then-'  
'I promised I wouldn't kill you. What else are you going to do? Face the teachers wrath? Your teacher is a mean guy, and wouldn't let you off easily. Besides, you write novels, you don't need studies.'  
Toko stopped, and considered this, her mind on her books again. Them hanging out together would be like a date, and experience would lead to her writing better stories right? It might be a good idea. Besides, if he tried anything funny Genocider would show no mercy. The thought of having to rely on that monster hurt, but it was convenient. 'Let's go then.'

They went into the town centre, trying to avoid suspicion. They decided they needed to lose the uniforms quickly, so they went to a clothes store. Korekiyo found a white dress which he thought would look good on her. It did, but when she saw the price she decided she wouldn't be able to afford it, or explain it to her parents.  
As if he could read her mind he said 'I can pay for it, I've got plenty of money.' She decided not to refuse.  
They bought food and ate in a park, and talked about themselves. They seemed to have more in common than they'd originally thought, and they both had parent issues.  
'My father abandoned us, and my mothers don't even care about me. I reckon then wish I didn't exist. I'm way too much of a burden.'  
'My parents practically disowned my sister and me when they found out about us. They pay the rent for my flat and send me money each month, but they refuse any contact with me.' Both of them wanted to talk about his sister, but they decided not to.  
The day went smoothly, and they learnt a lot about each other. They also had some fun running away from figures of authority who believed they ought to be in school.

'I guess the others would be leaving school around now. You can head home now if you wish.'  
It was then that Toko started to worry again. 'If my parents see me in this, they'll flip. But I don't want to just chuck it away either, seeing as it was so expensive. Could you keep it at your flat for me please?'  
'Of course I can. Today was fun, I'd like to do it again sometime, though maybe at a weekend next time.'  
'I would like that too. But just as friends ok, nothing more.'  
'Obviously.'  
Then they parted ways, and when Toko got home she immediately ran to her room and started writing. She could use their time together as inspiration. It later dawned on her that she hadn't asked about the mask, and vowed to ask tomorrow.

As he reached his flat Korekiyo was greeted by a neighbour. Once inside, he hung up the dress in his sister's cupboard, and took off the mask.  
'Someone's getting close to that mouse, aren't they? If you became good friends, you'd forget all about me, wouldn't you?'  
'No, I'd never-'  
'You won't, I'll make sure of that.'  
He prepared for a night of hell, being constantly chastised by his sister's ghost.

**Notes for the Chapter:**

> And there it is. I'm worried that it's a little OOC, but I'll try my best. No Genocider in this one, but she'll appear soon.


	3. Chapter 3

**Summary for the Chapter:**

> It's Toko's birthday now.

It was nearing the end of the school year, and Toko and Shinguuji were getting on well. She appreciated having a friend, and he liked having her around. He hadn't seen Genocider since the first time they met, but he often read about her latest victims in Serial Killer Monthly. However, on the 3rd of March Toko arrived at school looking upset, and Shinguuji soon greeted her.

'Happy 16th birthday Toko. Is something wrong?'  
'My mothers kicked me out of the house. Apparently I'm old enough to make do on my own. Tonight I have to gather my belongings and get lost. I guess I was too awful for them to even pretend to care.'  
'Don't say that, you're beautiful.'  
'Coming from you that's not a compliment. Now I'm homeless, and no supposed beauty will help me on the streets.'  
'You could stay at my place if you wanted. My sister's room is still free, take that.'  
'A m-man and a woman, under the S-same roof? You must have some ulterior motive.'  
'You know who I love and it's not you. Would you rather stay on the streets, where strangers may try to take advantage of you?'  
'F-fine I'll stay with you. Just don't try anything funny or else!'

Despite how quickly he had suggested it, Shinguuji was nervous. He didn't know if his apartment was good enough for her. Besides, his sister might try to interfere. Maybe she'd convince him to kill her, or do other things to make her hate him. He knew that he would have to keep her under control if he wanted this to work.  
Toko was terrified. She knew what men were like, and hoped that she would be safe. Despite how much she hated her other personality, she would have to rely on Genocider for help if things went wrong.

That evening, Toko packed her bags and left her home for the last time. Shinguuji helped carry them to his apartment, and he let her in. It was not the first time she had been to his house, but the first she had been able to explore it. His sister's room as bare, except from several pictures of the siblings together. She first noticed how similar the two looked, the only difference being the sister's makeup. Well, she assumed that one was the sister. She also noticed that Korekiyo wasn't wearing a mask in any of the pictures. She had asked about it before but only knew he started wearing it after his sister's death.

Toko unpacked quickly, and fell asleep almost immediately.  
Shinguuji also went to sleep, but was woken up with a pair of scissors at his throat.  
'What the fuck did you do to Toko? Why is she in your house?' Shinguuji just said nothing, but handed her a letter and tried to fall asleep again. However, Genocider wanted to talk for longer. 'Roommates huh? That sounds fun.'  
'Nice to see you again' he said sleepily, hoping she'd go away.  
'It has been a while hasn't it? Maybe a month or so. That would make it my birthday today right? What did you get me?'  
He pointed her towards a wrapped box, and she quickly opened it. She didn't know what it was until Shinguuji explained it to her.  
'They're for sharpening blades. I'm sure that your scissors must get pretty dull with all the stabbing.'  
'Hey nice! Thank you. I'm guessing you got something else for her.'  
'A new fountain pen. She seemed to like it.'  
At that, Genocider left the room. Shinguuji didn't know what she did next, but he didn't care.

'You gave her my room? Seriously?' This was what he had feared, his sister. 'You said that I'd be the only girl you'd ever look at, and now you're living with two of them. This is unacceptable.' And she continued with this until dawn.


	4. Chapter 4

**Summary for the Chapter:**

> Toko has fallen in love again, and the other two want to kill.

'So how's miss Gloomy? Found any new hotties to obsess over?' When Shinguuji had woken up he found Genocider in the kitchen eating cereal. She was quick to get used to her new accommodation.  
'There is a boy. Haru Suzuki. He is in the same year as you, but not the same class.' Shinguuji had heard Toko talk about this boy constantly, praising him as a god. But from his observations, he was arrogant, and a bully. However, he did not say this to Toko.  
'What the hell. He sounds generic as fuck. Is he single or what?'  
'He has a girlfriend, Mai, and cheats on her with several other girls.'  
'Sounds like an asshole. What does she see in him?' It was a question both of them had thought about before, unable to find an answer. 'If he does anything to hurt Toko tell me and I'll have an excuse to kill him. Anyway, it doesn't seem like Toko is going to be around today, want to skip school with me?'

The two of them decided to go see a movie together. After buying tickets for the latest horror movie, they had some time to buy popcorn. Whilst waiting, Shinguuji saw a familiar face. He pointed out Haru, with one of him side chicks. Genocider found him handsome, but was overcome with an urge to kill him.  
'Please don't. You'd get blood on your dress.'  
'I wouldn't have time before the film started.' Also, she had to make careful plans, so she wouldn't be caught. She also had to wait until he noticed Toko, and bullied her. She knew it would happen, but she didn't know when.  
She decided to not think too much about it until the movie was over, as she was excited about it.

As they were leaving the theatre, they started complaining about the movie.  
'And it was so predictable as well! God, it was obvious who the killer was, I could barely handle how stupid they were.' After saying this she sneezed.  
'I agree. The way she conveniently didn't show her face in any of the photos was the first clue. And then there was how she, or her sister to be exact, had been introduced only to be killed immediately for no reason. But in the end, they figured it out, as if they were geniuses. But I must say, her actual death was extremely beautiful, they took a risk being so crazy but-'  
'Death? Did you kill someone? Did I kill someone?' Toko was back, and had heard his analysis. 'And what time is it? Are we skipping school again?'  
'Oh no, I was talking about the movie Syo and I saw.' He didn't comment on their truancy.  
'Must have been horrible, I'd rather see a romance.'

'Oh is that her? The author of all those books?' They turned to see Haru and the woman walking by them. 'I love those! But she's so plain, it's boring.' Toko took one glance at her, and deduced she was a woman who put too much effort into her looks. She wouldn't appreciate the true meaning of her literature.  
'Yeah, she's a loser shut-in. I reckon she writes books to distract herself from her non-existent love life.' They didn't know that Toko and Shinguuji could hear them, as they were trying to be quiet. 'She's obviously in love with me though, she's such an annoying stalker. I wish she'd get lost.'   
'And who's that weirdo with her? I can't tell if it's a guy or a girl. Either way, really creepy.  
They continued talking trash until they were out of sight, and Toko started crying on Shinguuji's shoulder.  
'He's a jerk isn't he?'  
'I hate him I hate him I hate him. At least you had the guts to attack me directly.'  
'What if he died?' He knew that Genocider wanted to do it, but he wanted to know how Toko felt as well.  
'I don't care if he dies! I just want him gone.'   
'That can be arranged.'

Toko knew that she would regret this later, but right now she didn't care. As long as she never saw his awful face again.  
Shinguuji decided to tell Genocider immediately when he saw her again. There was someone that he wanted to kill too, and if she helped it would go smoothly.

**Notes for the Chapter:**

> Yay! Murder time soon.


	5. Chapter 5

**Summary for the Chapter:**

> The two murderers plan a double murder.

'I must kill Haru. What he did was unacceptable. He must be punished.' Genocider was livid after hearing Shinguuji's account. She had the intention to kill, and the scissors to kill with.   
'I want to help you. I have a plan, in which you can kill him and I can kill her.'   
'Her?'  
'His girlfriend Mai. She would make a good friend for my sister. She's kind, loyal and innocent. She is very naive, eating up all her boyfriend's lies. Who wouldn't want a friend like that? Bu-'  
'I wouldn't. She sounds too passive.'  
'But anyway, I have a murder plan. Let's do this together Syo.' Even if she refused, he would still ensure Mai's death, seeing as the last few friends he had found were average at best.   
'You said you had a plan?'

Genocider had never been inside the school at 1am, but there was a first for everything. After climbing over the locked gates, they had entered the school through a window. 'This feels all sneaky. You do this often?'   
'On occasion.'  
All they needed to do was leave a note:  
"Haru Suzuki, you are a filthy cheater, going with six girls at once. However, none of them know about this do they? If you do not want these photographs to be sent to all of them, stay at the school gates after school. We will give you further instructions from there."  
This was accompanied by photographs of Haru with all the girls. How Shinguuji had gotten these, she had no idea, especially the one of him in his room with a woman maybe 10 years older than him. But that didn't matter. As long as he took the bait, he would be dead within 24 hours, and so would Mai.

The two of them stayed away from their targets during the day, but they knew he had read the note. He was acting anxious, and he wouldn't look at Mai, even when she tried to speak with him. The guilt, or the fear of being caught, was obvious.  
After school, he stood at the gates for at least an hour after the school closed, waiting in the rain. He was restless, surely they should be here by now. Unless it was a stupid prank. He was about to leave, when his phone rang from an unknown number.  
'We are watching your every move. Follow all instructions, or-'  
'You'll release the photos right? What do you want? I'm broke.'   
'Do not ask questions, now turn left and start walking.'

After walking for about ten minutes, he found himself outside an abandoned apartment building. 'Enter the building, and wait there.' Once he entered, he looked around and saw a seemingly familiar face.   
'T-Toko? Are you the one who left that note?'  
'Half correct.'  
'I knew it. You are some crazy stalker after all. Just stay away from me ok. I know I can run faster than you, so if you come one step closer I'll be gone before you know it.'  
'No, you won't be able to leave. You see, you were only half correct.'  
'And I'm the other half.' Shinguuji attacked from behind and knocked him out. 'Now for part 2.'  
They took a photo of his uncommon figure with his own phone and sent it to Mai. She texted back immediately and was told to come to the same building.

'H-hello, Haru? Are you there?' As she walked in she saw his body and ran towards it. What she saw spread around it were several pictures - of Haru with other women. 'What is this?'   
'He was cheating on you Mai.' She turned and saw the two figures looming over her.  
'That's impossible. These must be fake.' She fell to her knees, turning for just a second. As this happened, Shinguuji hit her with a metal pipe, killing her instantly.   
'Kill him quickly, we don't know if others are following her.'   
'Are you kidding me? I like to take my time you know. If you're so worried then go outside and stand guard, and I'll have some private time with him.'  
'Whatever you say.' 

Half an hour later, Toko ran out of the building, covered in blood and tears.  
'H-Haru she really did that... I said I wanted him dead but I didn't-'  
'Toko calm down, we need to dispose of any evidence that could be linked to us.'  
'N-no way I'm not going b-back in there. I can't believe she killed a girl too. She only ever kills boys I like.'  
'She isn't the one that killed the girl.' Toko stared at him for a second, before running off once more. She soon tripped over on the slippery ground. Shinguuji helped her up.  
'Come on, let's get this over with. The past is the past.' But it seemed there was not much to clean up. Despite her violent methods, Genocider didn't leave any incriminating evidence. 'Let's go home.'

They the dinner in silence, after they washed off all the blood. Toko was terrified of the man in front of her, and Shinguuji was curious how she would react.  
'Did I ever tell you about anthropology? It's my area of interest.'   
'Never told me about it before.'  
'To put it shortly, it is the study of humanity. It is the subject my sister excelled in when she was alive, and I now try to follow in her footsteps. You know, she was offered a place at a prestigious academy for her work, but she died before she could attend it. I now wish to attend the same academy, to finish her work.'  
'What academy is that? I've never heard of a high school for anthropology.'  
'A place called Hope's Peak I believe. I believe they specialise in many things.'   
'I'd love to go there one day. To be a SHSL is to be guaranteed success in life. If I got in, people might treat me with respect.'  
'Maybe we could go together, you would be the SHSL romance author. I reckon you could make it.'  
'I might apply for it then.' Though this conversation, she had managed to forget the events of the day. She fell asleep satisfied.

Shinguuji prepared for another night of pain, having got little to no sleep for the past nights. However, his sister was unusually nice to him. 'I like this girl. You did well, brother.'

**Author's Note:**

> Yes, this is a ship now. I may update this soon, maybe it'll be a while.


End file.
